Weil-Mclain Ultra

Josh_10

Most jurisdictions don't require compliance with ASME standards. Generally just Universals Mechanical Code. In our state we don't have to comply with ASME unless you exceed 300,000 BTUH.

You will find that the boiler has very good built in high limit control features though. Additionally most residential boiler manufacturers don't include a manually resetable high limit control. It is not really a standard component.

Kevin_54

I was reading through the installation book for a Weil-Mclain Ultra boiler and read a note that says "If installation is to comply with ASME or Canadian requirements, an additional high temperature limit is needed. Install control in supply piping between boiler and isolation valve." My question is why dosen't it come as part of the factory installed electronic aquastat? and would a "strap-on" type aquastat work or should it be submerged in a well?

Josh_10

Most jurisdictions don't require compliance with ASME standards. Generally just Universals Mechanical Code. In our state we don't have to comply with ASME unless you exceed 300,000 BTUH.

You will find that the boiler has very good built in high limit control features though. Additionally most residential boiler manufacturers don't include a manually resetable high limit control. It is not really a standard component.

Weezbo

some locals state this is a requirement for boilers Over

a specified BTU/H rating others require it installed on any residential boilers in a commercial environment...i have not read the Canadian codes...however look for what i say in the interpretation of the code.

Tony_23

The biggest word

Is "If".

Most residential installs don't need to meet ASME. Over 3 units. Commercial applications, especially where the public is exposed.

Why factory install something that's rarely needed ?

BTW, I don't think you'll find a manual reset high limit in strap-on

Dread

Not yet, but it's coming.

Floyd

Check this out...

The Honeywell L4006H-1004 is a strap-on manual reset high limit. I have used them many times to satisfy the powers that be over the boiler worlds....a simple two wire hookup to the hard lock out terminals on the Ultra will give a O12 error, I believe, off of the top of my head. Of course the Ultra will lock out on it's own, somewhere just under 200....even hard one doubting Thomas that made me dial the limit back to 190 and run the boilers to that to prove that it would go into hard lockout. All this seems like major over kill when you are dealing with a boiler that will lock it's self out on a dry fire before it damages the boiler... Yup, and I can say first hand that it will do that... accidents DO happen....

Floyd

Josh_10

We can't use em around here except as a limit for air handlers. It would be nice though sometimes, but I can see the logic behind not allowing them on boilers.

Tony_23

I stand corrected

BUT, if I needed a MRHL, I wouldn't use a strap on. It's too easy for anybody to unstrap and leave it dangle, never to trip again. My experience with bldg maintenance handymen dictates that I install controls so they are more difficult to defeat.